Java has no internal representation for the imaginary number i. To compute with complex numbers in Java, you must import or create a package.

Notes for Python programmers:

The Wolfram Language provides a number of different stylized forms, such as ⅈ, ⅉ and for an imaginary number, and similarly for other constants, to maximize clarity. Additionally, the Wolfram Language will automatically infer whether or not a number is real or complex upon execution. Python by default uses the symbol j to represent an imaginary number, and in general operations will not necessarily work on them.

Sparse arrays are not provided by default in Java, typically requiring constructs from third-party libraries.

Notes for Python programmers:

In the Wolfram Language, it is easy to move between arrays and matrices using functions like MatrixForm. In Python, sparse arrays are not provided by default and require third-party libraries. Additionally, they are different classes, which will cause issues when moving between matrices in SciPy and arrays in NumPy.